Door of a machine tool



FIG. 1 is a front, right side and top perspective view of a door of a machine tool, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The areas shown in broken lines depict portions of the door of a machine tool that form no part of the claimed design. 

CLAIM The ornamental design for a door of a machine tool, as shown and described. 